1. Field of the Invention
The present invention relates to a marine vessel control system for a marine vessel that includes a marine vessel propulsion device, and to a marine vessel propulsion system and a marine vessel that include such a marine vessel control system.
2. Description of the Related Art
An exemplary marine vessel propulsion device is an outboard motor that is attached to a stern of a marine vessel. The outboard motor includes an engine, a propeller, and a shift mechanism. The shift mechanism is provided in a power transmission path between the engine and the propeller. The shift mechanism has a plurality of shift positions. The plurality of shift positions are a forward drive position, a neutral position, and a reverse drive position. The forward drive position is a shift position at which the rotation of a driveshaft that is driven by the engine is transmitted to the propeller shaft to rotate the propeller shaft in the forward drive direction. The reverse drive position is a shift position at which the rotation of the driveshaft is transmitted to the propeller shaft to rotate the propeller shaft in the reverse drive direction. The neutral position is a shift position at which the rotation of the driveshaft is not transmitted to the propeller shaft, that is, the power transmission path is interrupted.
The outboard motor is provided with a steering mechanism for changing the direction (steering angle) of the outboard motor with respect to the hull. The heading direction of the marine vessel can be adjusted by adjusting the steering angle. In some cases, the steering mechanism is arranged from a power steering apparatus that includes a steering actuator, such as an electromotive actuator, a hydraulic actuator, etc.
Steering of the marine vessel having the outboard motor includes adjustment of an engine output, selection of the shift position, and adjustment of the steering angle. The adjustment of the engine output and the selection of the shift position are performed by operation of a remote control lever included in a marine vessel maneuvering compartment. The adjustment of the steering angle is performed by operation of a steering handle included in the marine vessel maneuvering compartment.
In some cases, a drive-by-wire (DBW) system, which electrically transmits the operation of the remote control lever to the outboard motor, is adopted. In this case, a remote control unit includes a position sensor, which detects the operation of the remote control lever, and an electronic control unit (hereinafter referred to as “remote controller ECU”) that processes an output signal of the position sensor. The remote controller ECU outputs a throttle opening degree command (engine rotational speed command) and a shift position command. The outboard motor includes an electronic control unit (hereinafter referred to as “outboard motor ECU”) that processes the commands from the remote controller ECU. The outboard motor ECU controls a throttle opening degree of the engine in accordance with the throttle opening degree command and controls the shift position of the shift mechanism in accordance with the shift position command.
Likewise in some cases, a steer-by-wire (SBW) system, which electrically transmits the operation of the steering handle to the steering mechanism, is adopted. In this case, an operation angle sensor, which detects a rotation position of the steering handle, and an electronic control unit (hereinafter referred to as “steering ECU”) that processes an output signal of the operation angle sensor, are included. Also, a steering actuator is included as a power source in the steering mechanism. The steering ECU outputs a steering angle command. The steering angle command is sent to the outboard motor ECU. The outboard motor ECU controls the steering actuator based on the steering angle command.
Connection between the remote controller ECU and the outboard motor ECU is made by a communication bus. In the case where the steering ECU is included, the steering ECU is also connected to the communication bus. Communication between the remote controller ECU and the outboard motor ECU and communication between the steering ECU and the outboard motor ECU are performed via the communication bus.
In some cases, a marine vessel is provided with a plurality of marine vessel maneuvering compartments. For example, in some cases, a marine vessel structure includes a main marine vessel maneuvering compartment disposed at a first floor and a submarine vessel maneuvering compartment disposed at a second floor. There are also cases in which a marine vessel structure includes a main marine vessel maneuvering compartment disposed at a hull center, a first sub marine vessel maneuvering compartment disposed near a stem, and a second submarine vessel maneuvering compartment disposed near a stern. In such cases where a plurality of marine vessel maneuvering compartments are provided, each marine vessel maneuvering compartment includes a remote controller ECU and a steering ECU, and all of these are connected to the communication bus.
Meanwhile, the number of outboard motors is also not limited to one. For example, a multiple-outboard motor equipped arrangement, in which two or more outboard motors are attached side-by-side to the stern, is adopted in some cases. In this case, a remote controller ECU is provided for each outboard motor, and to each outboard motor ECU, the corresponding remote controller ECU is connected via a communication bus. Communication buses of a number corresponding to the number of outboard motors are thus provided.
When a disconnection or other fault occurs in the communication bus, marine vessel maneuvering control information (throttle opening degree command, shift position command, steering angle command, etc.) cannot be provided from the remote controller ECU or the steering ECU to the outboard motor ECU. Thus, in United States Patent Application Publication No. US 2007/082567 A1, the communication bus is arranged as a dual system. That is, the connection between a remote controller ECU and an outboard motor ECU is made by two communication buses. Thus, even when a fault occurs in one of the communication buses, communication among the ECUs can be performed via the other communication bus.